Corneal Aberrations and Reading
PURPOSE: To investigate the effects of eyelid pressure on corneal shape and corneal aberrations during reading. METHODS: Twenty young subjects with normal ocular health were recruited for the study. The experiment was conducted early in the morning, with subjects instructed not to perform any prolonged reading before the experiment. Corneal topography of one eye was measured with a videokeratoscope before reading and then again after a 60-min reading task. The natural position of the eyelids was photographed in primary gaze and during the reading task. RESULTS: Twelve of the 20 corneas showed significant changes in central topography immediately after reading. The location of the changes corresponded closely to the position and angle of the subject's eyelids during reading. The change in shape was best described as a wave-like distortion that significantly altered some corneal wavefront Zernike coefficients. There was a significant correlation between the changes in primary vertical coma and trefoil (along 30 degrees). Within the central 6 mm of the cornea, there were significant changes in the root mean square error, overall refractive power, and astigmatism. CONCLUSIONS: The changes we observed in corneal topography appear to be directly related to the force exerted by the eyelids during reading. Because the cornea is the major light-refracting surface of the eye, the optical characteristics of some eyes can be significantly changed during reading by the force of the eyelids. These findings may have important implications for the definition of refractive status and may also aid in the understanding of the relationship between reading and the development of refractive errors.
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|Item Type:||Journal Article|
|Additional Information:||The contents of this journal can be freely accessed online via the journal’s web page (see link) 12 months after publication. For more information, please refer to the journal’s website (see link) or contact the author. Author contact details: firstname.lastname@example.org|
|Keywords:||Corneal Topography, Reading, Cornea/, physiology, Eyelids/, physiology, Adult, Blinking/physiology, Humans, Refraction, Ocular, Refractive Errors/physiopathology|
|Subjects:||Australian and New Zealand Standard Research Classification > MEDICAL AND HEALTH SCIENCES (110000) > OPTOMETRY AND OPHTHALMOLOGY (111300)|
|Divisions:||Current > QUT Faculties and Divisions > Faculty of Health|
Current > Institutes > Institute of Health and Biomedical Innovation
|Copyright Owner:||Copyright 2003 Lippincott Williams & Wilkins|
|Deposited On:||25 Jul 2007|
|Last Modified:||29 Feb 2012 23:00|
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